Provides an architectural model of the OSI Network Layer as a frame for OSI Network Layer standardization. Is intended for use in the design and applicable of Network Layer protocols. To be used to provide a common set of concepts and terminology for Network Layer standards; to analyse Network Layer functionality and classify Network Layer protocols; to specify the use of "real network" in supporting or providing the OSI Network Service, above all, in cases where multiple "real network" are to be interconnected and used.